全文获取类型
收费全文 | 637篇 |
免费 | 19篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 29篇 |
妇产科学 | 24篇 |
基础医学 | 60篇 |
口腔科学 | 11篇 |
临床医学 | 48篇 |
内科学 | 109篇 |
皮肤病学 | 17篇 |
神经病学 | 24篇 |
特种医学 | 56篇 |
外科学 | 52篇 |
综合类 | 61篇 |
预防医学 | 14篇 |
眼科学 | 3篇 |
药学 | 66篇 |
肿瘤学 | 106篇 |
出版年
2024年 | 2篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 12篇 |
2014年 | 18篇 |
2013年 | 21篇 |
2012年 | 31篇 |
2011年 | 28篇 |
2010年 | 29篇 |
2009年 | 24篇 |
2008年 | 34篇 |
2007年 | 34篇 |
2006年 | 34篇 |
2005年 | 20篇 |
2004年 | 16篇 |
2003年 | 15篇 |
2002年 | 12篇 |
2001年 | 14篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 29篇 |
1997年 | 38篇 |
1996年 | 30篇 |
1995年 | 20篇 |
1994年 | 16篇 |
1993年 | 19篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 3篇 |
1985年 | 20篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1975年 | 6篇 |
1974年 | 3篇 |
1963年 | 1篇 |
1934年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
671.
672.
673.
674.
背景和目的:对于单用吸入糖皮质激素控制不佳的成人支气管哮喘(简称哮喘)患者,加用长效β-受体激动剂(LABA)可有效改善患者的症状及肺功能.但是最近对LABA长期治疗的安全性受到了美国食品药品管理局(FDA)及部分哮喘专家的质疑.另外,鉴于每个哮喘患者对治疗的反应不尽相同,因此寻求未控制哮喘患者的其他治疗方法是必要的. 相似文献
675.
676.
Cannabis is the most consumed illegal drug in Europe and its repercussions are more important when taken up at an early age. The aim of this study is to analyse and quantify the predictive value of different personal, family and environmental variables on the consumption of cannabis in adolescence. The sample is made up of 9284 adolescents (47.1% boys and 52.9% girls) with an average age of 15.59 years (SE=1.17). The ZINB model highlights, as factors that increase the number of joints consumed per week, consumption by the peer group, nights out during the week, gender, the production of forbidden behaviour and the use of other substances, whereas the risk factors for the consumption of cannabis are consumption by friends, ease of access, production of forbidden behaviour and the use of other substances. Association rules highlight the relationship between cannabis consumption, ease of access, production of forbidden behaviour and tobacco consumption. Finally, decision trees enable us to predict cannabis consumption as well as the number of joints an adolescent will consume per week based on the production of forbidden behaviour, consumption of other substances and number of friends who consume cannabis. The results of this work have practical implications concerning the prevention of cannabis consumption in an adolescent population. 相似文献
677.
678.
ObjectiveTo examine the phytochemical parameters of Aloe vera (A. vera) L. which can be used as a tool for its standardization.MethodsThe phytochemical analysis, solubility test, heavy metal analysis, antimicrobial study and quantitative analysis of gallic acid and berberine by HPTLC method were included in present study.ResultsPhytochemical analysis revealed the presence of alkaloid, carbohydrate, tannin, steroid, triterpenoid and glycoside. Total flavonoid and phenol content was found to be 1.9% and 13.11%. Concentartion of lead, arsenic, mercury and cadmium was found to be under the limit. Total bacterial count, yeast and moulds contents were found to be under the limit whereas Escherichia coli (E. coli) and salmonella was found to be absent in the extract. Quantitative analysis through HPTLC revealed the presence of 2.74% and 0.543% w/w of berberine and gallic acid.ConclusionsThe results indicate that the plant extract are rich in berberine and gallic acid implying their importance to human health. This investigation could be used as source of standard parameters which can play an important role in its standardization. 相似文献
679.
680.